Nanoparticle separation methods and compositions

Methods of separating one type of nanoparticle from another type of nanoparticle in a mixture including more than one type of nanoparticle are disclosed. The methods may include suspending a mixture of the various types of nanoparticles in a liquid and modifying a characteristic of the liquid. Thereafter, a force may be applied to the nanoparticles within the mixture causing one type of nanoparticles to separate from another type of nanoparticles. The applied force may be the force of gravity, or it may be an induced force such as a centrifugal force applied with a centrifuge or similar apparatus. Upon the occurrence physical separation, sub-populations of nanoparticles may be removed from the suspension or segregated. Alternatively the methods may include modifying a type of nanoparticle in suspension. Alternative embodiments include nanoparticles modified in suspension to provide for separation from other types of nanoparticles.